package com.atguigu.gulimall.cart.interceptor;

/**
 * Copyright (c) 2019-2029 星大陆 All Rights Reserved
 * <p>
 * Project: gulimall
 * Package: com.atguigu.gulimall.cart.interceptor
 * Version: V 1.0
 * <p>  在执行目标方法之前，判断用户的登录状态。并封装传递给 controller 目标请求
 * Created by guoxiaolong on 2021/01/15 13:57
 */

import com.atguigu.common.constant.AuthServerConstant;
import com.atguigu.common.constant.CartConstant;
import com.atguigu.common.vo.MemberResponseVo;
import com.atguigu.gulimall.cart.vo.UserInfoTo;
import org.apache.commons.lang.StringUtils;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.util.UUID;

public class CartInterceptor implements HandlerInterceptor {

    public static ThreadLocal<UserInfoTo> threadLocal = new ThreadLocal<>();

    /**
     * 目标方法执行之前
     *
     * @param request
     * @param response
     * @param handler
     * @return
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

        UserInfoTo userInfoTo = new UserInfoTo();

        HttpSession session = request.getSession();
        MemberResponseVo member = (MemberResponseVo) session.getAttribute(AuthServerConstant.LOGIN_USER);

        if (member != null) {
            //用户登录
            userInfoTo.setUserId(member.getId());
        } else {
            Cookie[] cookies = request.getCookies();
            if (cookies != null) {
                for (Cookie cookie : cookies) {
                    //user-key
                    String name = cookie.getName();
                    if (name.equals(CartConstant.TEMP_USER_COOKIE_NAME)) {
                        userInfoTo.setUserKey(cookie.getValue());
                        userInfoTo.setTempUser(true);
                    }
                }
            }
        }

        //如果没有临时用户一定分配一个临时用户
        if (StringUtils.isEmpty(userInfoTo.getUserKey())) {
            String uuid = UUID.randomUUID().toString();
            userInfoTo.setUserKey(uuid);
        }

        //目标方法执行之后
        threadLocal.set(userInfoTo);
        return true;
    }


    /**
     * 业务执行之后；分配临时用户，让浏览器保存
     *
     * @param request
     * @param response
     * @param handler
     * @param modelAndView
     * @throws Exception
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {

        UserInfoTo userInfoTo = threadLocal.get();
        //如果没有临时用户，一定保存一个临时用户
        if (!userInfoTo.isTempUser()) {
            //持续的延长临时用户的过期时间
            Cookie cookie = new Cookie(CartConstant.TEMP_USER_COOKIE_NAME, userInfoTo.getUserKey());
            cookie.setDomain("gulimall.com");
            cookie.setMaxAge(CartConstant.TEMP_USER_COOKIE_TIMEOUT);
            response.addCookie(cookie);
        }
    }
}

























